chassis repair advice needed

[Phil Parkinson]

I have a '63 Dart GP which has had the original floorpan redrilled and riveted.when you pick it up it already rattles from the old rivets .When I remove the floorpan to replace it I guess the rattle will only increase. So should I drill a large hole and remove all the old rivet remnants and the either fill the and holes with ? epoxy or weld them. I have been told welding ( MIG ) will put too much heat into the frame, which could cause sagging. Any advice from those who have tackled this problem greatly appreciated.
Thanks
Phil

[Rob Voska]

Can you hear them when the kart is running? I don't really see a problem but you can turn the frame up on end & squeeze some silicone in to glue them in place.

[Phil Parkinson]

Thanks Rob, I have had that suggestion of silicone or some of that expanding foam . What would you suggest about the holes as I think it will be almost impossible to drill a set in the new floor pan to match the existing Chassis holes. There are 2 sets of holes in the chassis already !

[Mike Reller]

Any decent welder could reweld your floor pan, without any affect on the structural integrity of the frame. Welding sheet metal to tubing is very common. It's how most old karts were built, even before any form of inert gas welding was common. You could also consider drilling out the rivets, tapping the holes, and using round head socket head cap screws (allen). Use round head to avoid skin removal when you grab it.
Rivets are great for some things. In high vibration and flexing applications, they are usually spaced closely together. Just look at an airplane skin. I'd weld it. That's just my opinion.

[Rob Voska]

Ever seen a hole duplicator? http://www.aircraftspruce.com/menus/to/ ... tters.html

[Scott Kneisel]

I also have a '63 GP with an aluminum riveted pan, it was the green one at TBO if you were there. Mine had also been removed once and replaced re-drilling many of the holes. What I did was to select the holes I thought were original and duplicate the pattern on the new pan. I left the second set of holes as is and have been running the kart hard all summer without a problem. I did use steel rivets so the pan actually helps strengthen the frame and yes, my kart sounds like a rain stick when you put it up on end. Doesn't bother me a bit. Can't hear it at all when I am driving!!

I would stay with an aluminum pan as the kart was manufactured. Welding on a steel pan will make it heavier and probably effect the handling a bit. If it makes you feel better, weld up one set of holes, it shouldn't hurt the frame if you use the right heat filler. It is a chrome moly frame with a very thin wall thickness so be careful.

That is my 2 cents.
Scott

[John Tzortzoudakis]

Phil
I'm currently replacing a welded-in pan on a Fireball Futura.
I wish I could use silicon to fix the problems with my floorpan I do like the idea of throwing glue at rivit remains inside frame tubes. I ussually drill a hole, drained out the pieces then welded up the hole again.

I have link below to a few pictures of what it takes to replace a welded in floorpan along with other 'farm-implement" style repairs.
This is probably an "extreme" example compared to your Dart. Maybe view it as encouragment; at least to say your lucky your kart isn't as bad as mine
Scroll down to the bottom of this page to see the floor pan work:
http://www.mccullochkartengine.com/news/default.htm

[Phil Parkinson]

Thanks to all for your advice and encouragement.
Vince I have never seen a hole duplicator , looks like a 'modified set af tweezers (wonder if I could make one????)
Scott, I would love to have been at The Big One but as you will see from my address it would be quite costly ...maybe one day! Steel Rivets sounds the right suggestion..
I hope to remove the floor pan this weekend , weather permitting. It will be interesting to see what lurks beneath as it has not been removed since the kart was made.
Cheers
Phil

[Rob Voska]

Duplicator has a little post on one side that drops thru the hole & the other has a drill bushing for drilling the pan. Works slick & is an aircraft repair item.